Syringe



NOV- 9, 1937. J. T. GoLTMAN Er Al. 2,098,658

SYRINGE Filed Feb. 28, 1935 Patented Nov. 9, 1937 UNITED, STATES PATENT oFFleE SYRINGE of Iowa Application February 28, 1935, Serial No. 8,604

6 Claims.

This invention relates to improvements in syringes and the like.

An object has been to provide an improved syringe which will prevent liquid and the like from gaining access to the common rubber bulb or other compressible member used in syringes. It is a well-known fact that liquids work their way up into the compressible members of syringes, and in addition to corroding the same and renlo dering the device short-lived, much liquid is wasted. To overcome this disadvantage we have provided an arrangement of a syringe having a plunger which renders it impossible for a liquid to gain access to the plunger and also eliminates Wastage of liquids or other materials.

An object has also been to provide a device of this kind which is relatively simple in structure and assembly and inexpensive to produce.

These and other objects and advantages will be more apparent hereinafter.

Our invention may be best understood by reference to the accompanying drawing, in which:

Fig. 1 is a front elevation of the device; Fig. 2- is a sectional view on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged sectional view on the line 3-3 of Fig. 2; f

Fig. 4 is an enlarged sectional view of the reciprocating plunger; and Fig. 5 is an enlarged end view of the plunger.

The preferred form of our invention which has been selected for illustrating the principle thereof comprises a glass tube I0 having at one end a flange II, particularly shown in Figs. l and 2, about which tube I0 and against which flange I I a common rubber bulb I2 having a neck I3 is adapted to be positioned. At the other end the glass tube has an inclined flange I 4 provided with a central aperture I5. Integrally and interiorly formed in the tube I0 is a glasstube I6 by means of integrally flared portions I1.

Adapted to reciprocate between the tubes I0 and I6 is a reciprocating plunger I8 shown in detail in Fig. 4. The plunger has a bore I9 and a closed end 20. The circumference of the bore I9 is only very slightly larger than the outer circumference of the tube I6 to allow the plunger I8 to iit upon the tube I6. The plunger I8 is provided with sealing flanges 2|, 22, and 23, and two of these flanges are provided in the form shown with port holes, there being a port hole 24 in flange 23 and a port hole 25 in flange 22. These flanges extend to the tube I0, anda workable, tight sliding fit is made between the plunger and tubes I0 (Cl. 12S-231) and I Ii, as will be well understood by those skilled in the art.

The end 20 of the plunger and the flange 23 and the end of the tube lil form a chamber 26 as shown in Figs. 1 and 2, and the flanges 22 and 5 23 have between them a chamber 2l, and the llanges 2| and 2,2 have between them a chamber 28, as will be seen clearly from Fig. 2, and the ange 2| and the flared portion I'I form another chamber 29. It will be understood that there is a l0 bore 30 in the tube I6.

With respect to the operation of the device, when the tube of the device as shown in the condition of Figs. l and 2 is compressed, air from the tube will force the plunger tothe rightY as shown l5 in Figs. 1 and 2 and force the air from chamber 26. If the device has been inserted into a liquid and then the tube is allowed to expand the liquid will be drawn up into the chamber 26, as will be manifest. When it is desired to expel the liquid, 2O the tube I2 may be compressed, and the liquid will be expelled. It will be seen that by the means we have provided it will be impossible for a liquid to work its way into the rubber bulb I2. In order for liquid to reach the bulb it would be necessary 25 first for the liquid to work around the flange 23 and into the chamber 2l, and thence around the flange 22 into the chamber 28, and thence around the flange 2| into the chamber 29. It would then be necessary for the liquid to wo-rk between the 30 plunger I8 and the tube I6 to the closed end 20 of the plunger, and it would then be necessary for the liquid to work upwardly through the tube I6. By means of the structure provided including the flanges `and the close-fitting workable sliding rela- 35 tionship between the parts, as will be manifest to those skilled in the art, it will be as a practical matter impossible for liquid to gain access to the rubber bulb I2. The port holes 2li and 25 are not necessary by any means. If it should be found 40 that a small amount of liquid should work its way into the chamber 21 or the chamber 28, the port holes may serve to allow the liquid to work its Way back into the chamber 26 and out of the device. 45

While we have shown three flanges, the flanges may be of any number greater or less than those provided, and in fact the plunger body might be made to completely seal off the space between the tube I6 and the tube I0 instead of using flanges, 50 and other modifications of the plungerV might be made to accomplish the same purpose.

While we have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation 55 1. In a device of the kind described, an exte; rior tube, an interior tube secured inL said eX-I"v terior tube and having its walls spaced from the walls of said exterior tube, and means to prevent liquid from said exterior tube entering said interior tube, said means comprising a reciprocaty ing plunger inclosed within said exterior tube and adapted to reciprocate between the walls of said tubes and form a closure for said interior` tube.

2. In a device of the kind described an exterior tube, a tubular plunger therein having a closed end and adapted to effect a seal therewith, and an interior tube extending into said tubular plunger and adapted to provide a seal therewith.V

3. In a device of the kind described, an exterior tube, an interior tube having its interior chamber sealed from the chamber of the exterior tube, and a reciprocating plunger in said exterior tube substantially inclosing said interior tube and adapted to eiect said seal.

4. In a device of the kind described, an exterior tube, an interior open end tube having one end secured to said exterior tube and providing a seal therewith, and an elongated hollow plunger adapted to telescope and form a closure for the opposite end or" said interior tube and provide a double seal between said tubes.

5. A device of the character described comprising an exterior tube, an interior tube extending into said exterior tube in substantial spaced relation thereto and having an open end within said exterior tube, and a piunger cap for said open end, said plunger having a tubular extending portion adapted to reciprocate between the Walls of said exterior and interior tubes and form a double seal therebetween.

6. A device ofv `the character described comprisingra tubular member having a bulb attached at one end and an orifice at the other end, an f elongated hollow plunger in said tubular member and adapted to provide a seal therewith, an

elongated tubular member secured in said rst tubular member and having one end thereof ared out and sealed to said rst tubular member adjacent the said bulb end thereof, said inner tubular member being substantially the length of said plunger and adapted to extend into and provide a seal with the inner walls thereof, whereby said plunger is reciprocable by i'luid pressure from said bulb.

JOI-IN T. GOL'IMAN.

JOHN W. ROBBINS. 

